Interplanetary magnetic field

Solar wind

Magnetic field

Ionosphere

Physics

Electron density

Geology

Astronomy

Magnetosphere

Geodesy

Plasma sheet

Total electron content

Earth's magnetic field

Geomagnetic latitude

Polar

Computational physics

F region

Quantum mechanics

Geophysics

Plasma

Atmospheric sciences

Journal of Geophysical Research Space Physics

The polar ionosphere is often characterized by irregularities and fluctuations in the plasma density. We present a statistical study of ionospheric plasma irregularities based on the observations from the European Space Agency's Swarm mission. The in situ electron density obtained with the Langmuir probe and the total electron content from the onboard global positioning system receiver are used to detect ionospheric plasma irregularities. We derive the irregularity parameters from the electron density in terms of the rate of change of density index and electron density gradients. We also use the rate of change of total electron content index as the irregularity parameter based on the global positioning system data. The background electron density and plasma irregularities are closely controlled by the Earth's magnetic field, with averaged enhancements close to the magnetic poles. The climatological maps in magnetic latitude/magnetic local time coordinates show predominant plasma irregularities near the dayside cusp, polar cap, and nightside auroral oval. These irregularities may be associated with large‐scale plasma structures such as polar cap patches, auroral blobs, auroral particle precipitation, and the equatorward wall of the ionospheric trough. The spatial distributions of irregularities depend on the interplanetary magnetic field (IMF). By filtering the irregularity parameters according to IMF B y , we find a clear asymmetry of the spatial distribution in the cusp and polar cap between the Northern (NH) and Southern Hemispheres (SH). For negative IMF B y , irregularities are stronger in the dusk (dawn) sector in the NH (SH) and vice versa. This feature is in agreement with the high‐latitude ionospheric convection pattern that is regulated by the IMF B y component. The plasma irregularities are also controlled by the solar activity within the current declining solar cycle. The irregularities in the SH polar cap show a seasonal variation with higher values from September to April, while the seasonal variation in the NH is only obvious around solar maximum during 2014–2015.

Ionospheric Plasma Irregularities Characterized by the Swarm Satellites: Statistics at High Latitudes